1. Field of the Invention
The present invention relates generally to a machine tool, and more particularly to a sawing machine having an assembly for dustproof.
2. Description of the Related Art
FIG. 1 shows a conventional sawing machine mainly having a casing 1, a transmission assembly 2, a movable cover 3 and a saw blade 4. The transmission assembly 2 has a motor 2a mounted at an outer side of the casing 1, a bearing mount 2b mounted at an inner side of the casing 1 and a transmission shaft 2c running through the bearing mount 2a, wherein the bearing mount 2b has an axle 2d projected out, the movable cover 3 has an annular rim 3a and an arched block plate 3b to engage the rim 3a with the axle 2d so that the movable cover 3 swings with the axle 2d to be the center of rotation. The saw blade 4 connects with the transmission shaft 2c and has a part thereof covered by the block plate 3b. A separating device 5 is provided in between the movable cover 3 and saw blade 4 to keep the saw blade 4 running smoothly. When the sawing machine is cutting a specific object A, as shown in FIG. 2, the movable cover 3 has its front end in contact with the object A and moves along with it. In the meantime of the object A running forwardly, the movable cover 3 swings backwardly so that the movable cover 3 always can block the chips of the object A being sawn.
It is always occurred in the conventional sawing machine that the chips run into the space between the rim 3a and the axle 2d and are accumulated therein to make the movable cover 3 can not swing smoothly. Beside that, the movable cover was made of aluminum so that while a metal object was sawn by the machine, the metal chips accumulated in between the rim and the axle damage the movable cover frequently.
The primary objective of the present invention is to provide a sawing machine having a dustproof assembly to block the sawing chips so that the movable cover always works correctly in sawing procedures.
According to the objective of the present invention, a sawing machine comprises a casing having a chamber therein, an axle hole at a side thereof and an opening at a bottom thereof. Both of the axle hole and the opening communicate with the chamber. A transmission assembly has a bearing mount mounted at an inner side of the casing having a base board and an axle projected from a side of the base board, a transmission shaft running through the bearing mount and the axle hole and a power resource for driving the transmission shaft to rotate. A movable cover has an annular rim and a block plate, wherein the rim has an inner annular face, an inner face and an outer face and is engaged with the axle of the bearing mount so that the movable cover swings around the axle which serves as a center of rotation. A first block ring is installed in between the bearing mount and the movable cover, wherein the first block ring is attached to the base board of the bearing mount and the rim of the movable cover respectively. A block device is provided at an outer side of the movable cover and has a mask and a second block ring, wherein the mask has a first hole for the transmission shaft running therethrough and the second block ring has opposite sides attached to the outer face of the rim of the movable cover and the mask respectively, and a saw blade is fastened at a distal end of the transmission shaft and is located at an outer side of the block device, wherein the saw blade has a part thereof extruded out of the casing via the opening and the extruded part thereof are covered by the block plate.